The present invention relates to a power tool in general, and especially to a power tool which is equipped with an arrangement for withdrawing particulate material from the vicinity of the tool element which is clamped in the chuck of the power tool.
Power tools of various constructions, among them hammer drills, are already known and used not only by professionals but also by do-it-yourselfers. The conventional power tools of this type used to let the particulate material removed from the workpiece or structure by the tool element escape freely into the environment. In view of the fact that the escaping particulate material, such as dust, chips or the like, will not only undesirably soil the environment of the working location, but may even create a health hazard to the user of the power tool, it has already been proposed to equip the power tool with, or to operate the power tool in conjunction with, an arrangement for collecting or confining the removed particulate material at the location where it is being removed from the structure being worked upon. In this context it has also been already proposed to equip the power tool with a blower which creates a stream of air which entrains the particulate material removed from the structure and carries it with it to a location distant from the operating location, for instance, for the particulate material to be collected at such a distant location.
Experience with this latter type of a power tool which is equipped with the blower has shown that the blower itself and the housing thereof, which are quite expensive and difficult-to-replace components of the power tool, suffer of a substantial amount of wear so that the lifespan of these components is much shorter than that of the remainder of the power tool. Experience has shown that this is attributable to the abrading or eroding action of the particulate material the particles of which may have, depending on the properties of the material of the structure being worked upon, sharp edges, especially when the material of the structure is brittle. This, of course, is very disadvantageous inasmuch as the premature wear of the blower or its housing calls either for frequent replacement of these components, at a substantial expense, or for discarding the entire power tool, which is also not economically supportable, or for the use of the power tool without the particulate material exhausting feature, which is not only inconvenient but may even be hazardous.